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Characterization of the murine H2–M3 wt ‐restricted CD8 response against a hydrophobic, protease‐resistant, phospholipid‐associated antigen from Listeria monocytogenes
Author(s) -
Kurlander Roger,
Nataraj Chandrasekaran
Publication year - 1997
Publication title -
immunological reviews
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.839
H-Index - 223
eISSN - 1600-065X
pISSN - 0105-2896
DOI - 10.1111/j.1600-065x.1997.tb00998.x
Subject(s) - antigen , biology , listeria monocytogenes , immune system , cardiolipin , protease , cytotoxic t cell , proteolysis , t cell , antigen processing , cd8 , microbiology and biotechnology , antigen presentation , biochemistry , phospholipid , bacteria , immunology , in vitro , enzyme , genetics , membrane
Summary: Mice infected with Listeria monocytogenes (LM) generate protective CD8 cells of varying specificity. One subset, unlike conventional LM‐immune CDS cells, can respond to antigen‐presenting cells (APC) treated with heat‐killed LM (HKLM), These cells proved to have surprisingly uniform specificity, recognizing a product we designated HKLM‐associated antigen (HAA) presented by the non‐classical dass Ib product H2–M3′. HAA proved to be extremely hydrophobic and the bioactive portion of the molecule was highly protease‐resistant, leading us initially to speculate that it might be a non‐peptide. Recent studies, however, identify HAA as a complex containing lemA, a listerial protein bearing the immunogenic amino terminal peptide sequence fMIGWII, tightly associated with bacterial cardiolipin. A variety of cell types can process and present exogenous HAA/lemA. and the phospholipid component appears essential for this processing. Endosomal acidification and proteolysis are required for processing, but the site where antigen binds to H2–M3 wt within APC remains uncertain. HAA/lemA‐immune effectors are unusually cross‐reactive. We could readily detect H2–M3 wt ‐restricted responses to APC incubated with unrelated N ‐formylated peptides, and bacteria, HAA‐like products represent an intriguing new set of bacterial antigens recognizable by immune CD8 cells.